This invention relates generally to bladder pressure measurement and/or monitoring systems, and more specifically concerns a system for determining a surrogate bladder pressure value using previously determined cystometry information.
The physical condition of high bladder pressure, eventually leading to over-distention of the bladder and typically caused by overfilling of the bladder, can in some cases lead to severe physical consequences, including bladder muscle damage, kidney cell damage and elevated blood pressure. With respect to bladder muscle damage, small tears can result in the bladder muscle and bladder wall, producing some tissue death in the bladder wall. In the kidneys, overfilling of the bladder can lead to back pressure which is transmitted through the ureters back into the kidneys, compromising the capillary profusion in the glomerulus (urine producing) portion of the kidneys, which often results in permanent damage to the kidneys. High bladder pressure can also have severe physiological effects within the bladder, including high infection rate, possible diverticula formation and stone formation.
Overfilling of the bladder can have a number of causes, including lack of attention to a patient who is under anesthesia during lengthy surgery. Overfilling is common in patients who experience some degree of bladder dysfunction, caused by injury (e.g. spinal cord injury), various bladder diseases, or other more general disorders which affect the bladder, including muscular sclerosis (MS), Parkinson""s disease and other diseases. Further, certain surgical procedures, such as prostate surgery, can result in the interruption (severing) of nerves to the bladder, which leads to bladder dysfunction. Still other causes include normal aging, as well as certain anxiety disorders.
All of the above factors can in some way affect or disrupt the coordination between the sphincter muscles and the bladder which account for the timely emptying of the bladder. The above bladder conditions, particularly for those situations, such as a severe spinal cord injury, where there is no sensation of bladder fullness at all, are treated by a technique referred to as intermittent catheterization. This can be done on a time basis, at precise time intervals; in many cases, however, the time basis approach results in more frequent catheterizations than necessary, which increases the chances of infection in the bladder area. In other cases, catheterization is not performed frequently enough, such as for smaller bladders. This leads to distention of the bladder.
Intermittent catheterization can also be performed using volume information determined by an external non-invasive device which measures the volume of urine in the bladder. However, the volumetric approach may, in some cases, not be optimum relative to the actual pressure in the bladder. Bladder pressure most likely provides the most accurate and the most appropriate basis for making a decision to perform a catheterization at a specific point in time. Up to this point, however, bladder pressure information has been available only through a quite invasive medical procedure, which cannot in practice be done on a sufficiently regular basis to be used for routine catheterization decisions.
Accordingly, the present invention includes a system and corresponding method for providing an indication of bladder pressure for a patient comprising: a bladder volume determining system for obtaining, i.e. determining, the volume of urine in the bladder of a patient; means comparing the bladder volume determination against a previously determined cystometry graph of bladder pressure versus bladder volume for the patient, so as to determine surrogate bladder pressure values from said bladder volume determinations; and an indicator for indicating said surrogate pressure.